Process and apparatus for treating biogenic residues, in particular sludges

摘要

In a process to dispose of sewage sludge organic residues dried in air at a temperature of 60 to 70C until they dry to a point at which they are capable of sustaining combustion. Evaporated water is discharged with moist air without liberation of volatile substances. The batches of dry matter are held in a primary intermediate store to equalise moisture content. A further quantity of dry matter is held in a secondary buffer store. Residual matter is then treated in a series of heat treatment stages, from each of which residues are removed. These residues are by primary and secondary cleaning stages. In the primary stage the residues are filtered and dust removed. In the secondary cleaning stage the material is exposed to adsorption. Energy is recovered from all stages of the process via a heat exchanger. The sewage sludge starts the process with between 2 and 35 per cent dry matter. Air employed in the drying process is pre-heated prior to use in the drying process. The sludge is dried primarily by internally-generated heat energy. Also claimed is a commensurate assembly.